package com.mars.miaosha.redis;

import com.alibaba.fastjson.JSON;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import redis.clients.jedis.Jedis;
import redis.clients.jedis.JedisPool;

/**
 * @author MARS
 * @date 2018/5/2
 */
@Service
public class RedisService {

    @Autowired
    JedisPool jedisPool;

    /**
     * 获取当前对象
     * @param key
     * @param clazz
     * @param <T>
     * @return
     */
    public <T> T get(KeyPrefix prefix,String key,Class<T> clazz){
        Jedis jedis = null;
        try {
            jedis = jedisPool.getResource();
            String realKey = prefix.getPrefix() + key;
            String str = jedis.get(realKey);
            T t = stringToBean(str,clazz);
            return t;
        } finally {
            returnToPool(jedis);
        }
    }

    /**
     * 设置redis保存
     * @param key
     * @param value
     * @param <T>
     * @return
     */
    public <T> boolean set(KeyPrefix prefix,String key,T value){
        Jedis jedis = null;
        try {
            jedis = jedisPool.getResource();
            String str = beanToString(value);

            if (str == null || str.length()<=0) {
                return false;
            }
            String realKey = prefix.getPrefix() + key;
            int seconds = prefix.expireSeconds();
            if(seconds <= 0 ){
                jedis.set(realKey,str);
            } else { // 设置key过期时间
                jedis.setex(realKey,seconds,str);
            }
            return true;
        } finally {
            returnToPool(jedis);
        }
    }


    /**
     * 判断key是否存在
     * @param prefix
     * @param key
     * @param <T>
     * @return
     */
    public <T> boolean exist(KeyPrefix prefix,String key){
        Jedis jedis = null;
        try {
            jedis = jedisPool.getResource();
            String realKey = prefix.getPrefix() + key;
            return jedis.exists(realKey);

        } finally {
            returnToPool(jedis);
        }
    }

    /**
     * 增加值
     * @param prefix
     * @param key
     * @param <T>
     * @return
     */
    public <T> Long incr(KeyPrefix prefix,String key){
        Jedis jedis = null;
        try{
            jedis = jedisPool.getResource();
            String realKey = prefix.getPrefix() + key;
            return jedis.incr(realKey);
        } finally {
            returnToPool(jedis);
        }
    }

    /**
     * 减少值
     * @param prefix
     * @param key
     * @param <T>
     * @return
     */
    public <T> Long decr(KeyPrefix prefix,String key){
        Jedis jedis = null;
        try{
            jedis = jedisPool.getResource();
            String realKey = prefix.getPrefix() + key;
            return jedis.decr(realKey);
        } finally {
            returnToPool(jedis);
        }
    }

    /**
     * 将bean对象转换为String
     * @param value
     * @param <T>
     * @return
     */
    private <T> String beanToString(T value) {
        if (value == null) {
            return null;
        }
        Class<?> clazz = value.getClass();
        if (clazz == int.class || clazz == Integer.class) {
            return "" + value;
        } else if (clazz == String.class) {
            return (String)value;
        } else if (clazz == long.class || clazz == Long.class) {
            return "" + value;
        } else {
            return JSON.toJSONString(value);
        }

    }

    /**
     * string转换为 T 对象
     * @param str
     * @param <T>
     * @return
     */
    private <T> T stringToBean(String str,Class<T> clazz) {
        if (str == null || str.length()<=0) {
            return null;
        }

        if (clazz == int.class || clazz == Integer.class) {
            return (T)Integer.valueOf(str);
        } else if (clazz == String.class) {
            return (T)str;
        } else if (clazz == long.class || clazz == Long.class) {
            return (T)Long.valueOf(str);
        } else {
            return JSON.toJavaObject(JSON.parseObject(str),clazz);
        }

    }

    /**
     * 释放redis连接
     * @param jedis
     */
    private void returnToPool(Jedis jedis) {
        if (jedis !=null) {
            jedis.close();
        }
    }


}
